DistributedLock.java

@Listener
public class DistributedLock {

    private static Logger log = Logger.getLogger(DistributedLock.class);

    private static final String KEY = "cassalog";

    private AdvancedCache<String, String> locksCache;

    public DistributedLock(AdvancedCache<String, String> locksCache) {
        this.locksCache = locksCache;
        this.locksCache.getCacheManager().addListener(this);
    }

    public boolean isLocked() {
        return getLockValue().equals(locksCache.get(KEY));
    }

    public boolean lock() {
        if (isLocked()) {
            return true;
        }
        String previous = locksCache.putIfAbsent(KEY, getLockValue());
        return previous == null;
    }

    public boolean release() {
        if (isLocked()) {
            return locksCache.remove(KEY, getLockValue());
        }
        return false;
    }

    @ViewChanged
    public void viewChanged(ViewChangedEvent event) {
        log.info("view changed: " + event);
        List<Address> old = new ArrayList<>(event.getOldMembers());
        old.removeAll(event.getNewMembers());
        for (Address address : old) {
            locksCache.remove(KEY, address.toString());
        }
    }

    private String getLockValue() {
        EmbeddedCacheManager cacheManager = locksCache.getCacheManager();
        Address address = cacheManager.getAddress();
        return address.toString();
    }

}